1. Field of the Invention
The present invention relates to an antenna, and more particularly, to an antenna using dual-polarized waves.
2. Description of the Related Art
Generally, vehicles use fossil fuel, electricity, etc. as a power source. Recently, in addition to transporting goods and humans, vehicles include audio devices and video devices and navigation devices. Currently, the need for communication between vehicles and external devices is gradually increasing. For example, a navigation function that indicates a path toward a destination requires information related to road traffic conditions to find an optimal path. Since such traffic conditions constantly change, it is necessary for vehicles to obtain information regarding traffic conditions in real time. Additionally, to provide safety and convenience of drivers, forward collision warning systems (FCWS), autonomous emergency braking (AEB) systems, etc. have been developed. Such FCWS or AEB systems may calculate whether a forward vehicle collides or not, an estimated collision time, etc. based on position information of the forward vehicle detected by a radar.
An apparatus for communicating with other vehicles and a radar device for warning of forward collision include an antenna which transmits and receives radio waves. Current vehicle antenna technology is limited to patch array antennas. Typically, antennas are light-weight and thin. However, patch array antennas have a dielectric loss that occurs due to the dielectric substrates and the performance of antennas is reduced due to the dielectric loss. In particular, fifth generation communication or radars typically use high frequency of several tens of GHz or greater, efficiency of patch antennas does not reach 30%. Additionally, since patch array antennas use a serial type feeding structure, narrow frequency band properties are available.